Chuck Thacker posed a little synchronization problem to me, which I solved with Jim Saxe's help. At that time, deriving concurrent algorithms was the fashion--the idea that you discover the algorithm by some form of black magic and then verify it was considered passé. So,…
Resistive ballooning modes are unstable in the first region of ideal ballooning stability. We show that in contrast the second region is largely stable to resistive ballooning modes.
Polymorphic means to have many forms. As related to programming languages, it refers to data or programs which have many types, or which operate on many types. There are several arbitrary ways in which programs can have many types; we are mostly interested in a…
In a paper published in 1978 (Needham & Schroeder) we presented protocols for the use of encryption for authentication in large networks of computers. Subsequently the protocols were criticised (Denning and Sacco) on the grounds that compromise of a session key and copying of an…
We demonstrate that classes of dependencies among beliefs held with uncertainty cannot be represented in rule-based systems in a natural or efficient manner. We trace these limitations to a fundamental difference between certain and uncertain reasoning. In particular, we show that beliefs held with certainty…
Several areas of research on problem-solving tradeoffs in reasoning systems are presented. Issues surrouding the valuation of computation in the context of computational resource constraints are introduced. Areas of research on problem-solving tradeoffs receiving ongoing attention include: (1) strategic control, (2) structural control, and (3)…
Department of Mathematics, The University of Utah, Masters Thesis
In 1979, Blackley and Shamir independently proposed schemes by which a secret can be divided into many shares which can be distributed to mutually suspicious agents. This paper describes a homomorphism property attained by these and several other secret sharing schemes which allows multiple secrets…
In the 1940's, a physicist named Cox provided the first formal justification for the axioms of probability based on the subjective or Bayesian interpretation. He showed that if a measure of belief satisfies several fundamental properties, then the measure must be some monotonic transformation of…
We consider two probabilistic interpretations for quantities found in the INTERNIST-1 knowledge base called evoking strengths. The first interpretation is based on the definition of evoking strengths while the second is based on the use of evoking strengths in the scoring scheme. We then describe…
In this paper, we distribute the functions of the government in the cryptographic election scheme of [CoFi85]. In so doing, we are able to achieve privacy of individual votes in a much stronger sense without giving up any of the previously attained properties of robustness…
